i've tried adjusting for arc, no matter how high i adjust for slope i get nothing. 85m just fine, 94m still bullseye, 101m nothing. except on the krogan colony world (can't remember how that's spelled), there i can get a hit at up to 110m or so, but everywhere else maximum range for me seems to be 100m or less.
---edit
i'm on elaaden (i had to write the name down lol) and i decided to tryout a widow (i actually don't like it all that much), using a widow i have a maximum effective range (maximum effective range meaning, maximum range a weapon can operate in without a noticeable degradation in performance) seems to be about 110m, though i can reliably strike targets at 170m, but only with a widow, i'd try a blackwidow though i don't have the research points for it atm. it's a shame i still don't like that particular weapon, nor do i think the maximum range is still sufficient for a sniper rifle. but this is noticeably better.